rear cab mounts broken and in need of serious reapir 48 3100

[OrangeOutlaw]

So here is my problem, how do i fix it?

There is a piece of 2x4 holding the cab up under the sheetmetal and running between both sides of the chassis.

I did not do this for the record, It was done by the last owner...

My fear is that if i just remove the 2x4 the cab will just fall to the chassis and possibly crack my running boards/dent the cab...

Has anyone had to fix this before and if so how did you do it/ how would you do it?

If i dont fix this now, the rips will just get larger...

More pictures at : photobucket.com/albums/u498/OrangeOutlaw1/

[55metalmonkey]

I had to fix this area on mine (TF though) mine was a bit more severe and I had to reverse engineer some hillbilly backyard repair work. I had to repair the floor pan, cab mounts and all the under bracing.

Pach pannels are available (see LMC online cat. pg 24) but that is mostly the whole floor pan, others suppliers sell just the patches. If you go the route I did they are not hard to make yorself if you have basic sheet metal skills and a few tools.
I went a little over the top when I did mine since I was showing my kid how to make negative press dies, small stamping tools, oversize dollies and sheet metal bucks but the whole thing could be done with hand tools and a mig welder.

[OrangeOutlaw]

Do you have before and after pictures?!?! I would love you for ever... Did you have to take the bed off to do it? what was the process and how long did it take you?

What i was thinking was to just take a 16 guage sheet and weld it over the spot, drill a hole, re mount... both sides... the passenger side should just be some welding without patch work?

[OrangeOutlaw]

Also do i need any special bolts to mount the cab? what are those bolts called?

Im such a newbie, but I am replacing it this weekend and need some serious suggestions.

Thanks again...

Any reposts would be great, i cant find anything, Also I would like to see what a picture of the cab looks like underneath in that area before it is mounted and after it is mounted...

[mr48chev]

That cab originally mounted with a center mount so that there were only three cab mounts holding it to the chassis.

The bolt that we see is something that someone else added later. What frame is under the truck?

LMC sells rear cab support pieces http://www.lmctruck.com/icatalog/ca/full.aspx?Page=24

[OrangeOutlaw]

I believe it is a 63 S10.

[55metalmonkey]

Originally Posted by OrangeOutlaw

Do you have before and after pictures?!?! I would love you for ever... Did you have to take the bed off to do it? what was the process and how long did it take you?

What i was thinking was to just take a 16 guage sheet and weld it over the spot, drill a hole, re mount... both sides... the passenger side should just be some welding without patch work?

I took a couple thousand pics of everything I've done so far but it will take a lil bit to dig through them. I'll look tonight, I'll post what I find. Keep in mind that mine is a TF so the overall configuration is different but the process is the same.
As for bed/cab on or off I did mine completely dissasembled and flipped the cab on it's back half way though to work on both sides to get it to look factory original and so the patch is indistigushable from the rest. took me a couple days but like I said I was teaching my kid a bunch of other things along the way. A realistic time frame for someone with average skills start to finnish would be 6hrs, not rushing and paying attention to details (which I'm sure you intend to do)

The link that mr48 posted is the page I was refering to. As for bolts on the cab carrige bolts are what look to be the original style, I used grade8 for bolts on my truck for everything, they really don't cost any more than standard grade, nothing to brag about btw but since these trucks are made with very few different size bolts it's just more simple to keep everything grade 8 (just my 1/50th of a $)

[48chvtrk]

The reason that it broke is that the floor was bolted directly to the frame . Being that it's a 48 cab there is no reinforcement there. Just replacing the floor won't prevent that from happening again. Every time someone gets in or out of your truck the floor is flexing in that area work hardening it ,eventually it's going to break .You'll need to reinforce it some how. Later AD cabs were mounted in that location via shackles . There is a channel type mount that reinforces the floor (http://www.chevsofthe40s.com/detail/..._SUPERIOR.html.) But, since your truck is modified the rules don't apply here. Perhaps you could use some rectangular tubing , maybe 14 gage 3/4" X 2" or 1" X 2" welded to the bottom of your patch ( 18 gage ?) Then run your bolt thru that. You may have to eliminate what appears to be a rubber donut body mount and replace it with a thinner solid piece of rubber. The bolt looks to be a 1/2" bolt . I would use a grade 5 ,available at Lowes or your local hardware store. Hope this helps. Bill

[55metalmonkey]

Sorry didn't have any time to get to my computer on the weekend and post up some pics.
this tread might have some usefull info
http://67-72chevytrucks.com/vboard/s...ght=cab+repair

Mr48 hit the nail on the head with reinforcing the area to prevent it from happening again.

[mr48chev]

The other problem is that when who ever built the truck they notched out the channel that gives that area it's support to clear the S-10 cab mounts.

The mount supports that we gave links to won't help a lot now as you will have to figure out a way to reinforce the floor after you repair it. That may be as simple as running a piece of flatbar across the width of the floor under that area or having a piece made to reinforce it.

[mr48chev]

In this photo I drew some lines where the support brace runs across your floor side to side.
When they put the cab on the S-10 frame they cut through the channel of that support to clear the cab mounts.


This is the piece that we suggested previously but won't really do you a lot of good.


My guess is that they missed that reinforced piece completely when they ran the bolts through to hold the cab in place. I'd also hazard a guess that they cut out the seat base sheet metal to install later model seats and that cross piece at the back of it serves as a reinforcement for the floor also. That's no biggie as long as you put some reinforcement back in the cab to help support the weight where it sits on the mounts.
I think I'd run a piece of 3/16 or 1/4 x 3 or 4 or maybe wider flat bar across under and above the floor to spread out the pressure and that would also give you a secure place to bolt your seat belts through.